Myristica trobogarii Govind & M. Dan, 2020

Govind, Murugan Govindakurup, Dan, Mathew & Rameshkumar, Koranappallil Bahuleyan, 2020, Myristica trobogarii (Myristicaceae), a new species from southern Western Ghats, India, Phytotaxa 437 (4), pp. 206-212 : 206-210

Myristica trobogarii Govind & M. Dan , sp. nov. ( Fig. 1 F–J & Fig 3 A–F )

Similar to M. malabarica but differs by its bright blood red bark exudates (vs. orange red); 26–30 cm long leaves (vs. 10–12 cm long), shortly acuminate leaf apex with undulate margin (vs. acute apex with entire margin); glabrous staminal column with 14 anthers (vs. pilose at base, with 10 anthers); glabrous ovary (vs. tomentose); ovoid, glabrous fruits with mucronate apex (vs. oblong, densely tomentose with rounded apex), orange yellow coloured rinds (vs. brown) and yellow arillate seeds (vs. orange red). ( Table 1)

TYPE:— INDIA. Kerala: Kollam district, Agasthyamala Biosphere Reserve, Sankily forest , 08°47ʹ36.27ʺN, 77°07ʹ32.65ʺE, 300 m a.s.l., 12 Mar 2017, Govind 81763 (Holotype: TBGT; Isotypes: MH, CALI) .

An evergreen, 15–25 m tall, dioecious tree; main trunk 90–120 cm in diameter, bark rough, greyish brown, exudate bright blood red coloured, watery, branching usually whorled. Leaves alternate, petiolate; petiole 2.8–3.1 cm long, deeply grooved, glabrous; lamina 26–30 × 10–13 cm, elliptic to oblong, apex shortly acuminate, margin undulate, base rounded, adaxially light green, gland-dotted, abaxially glaucous, glabrous; midvein prominent, lateral veins adaxially prominent, 15–17 paired. Male inflorescence 16–18 flowered, axillary umbel; peduncle erect, 2–3.5 cm long, cylindrical, tomentose. Flowers caducous, urceolate, 4.5–5.3 × 2.3–3 mm, yellowish-brown, pedicellate; pedicel 3.8–4.2 mm long, pubescent; bracteole 2.4–3.1 × 2.2–3.1 mm, ovate, acute at apex, appressed to the base of male flower, dorsally convex, brown, densely tomentose outside, persistent. Perianth fleshy, lobes 3 (rarely 4), equal, acute, re-curved outward, yellowish-brown, densely pubescent outside; staminal column 3.2–3.5 mm long, cylindrical, with a shallow groove just below anthers, glabrous; anthers 14, with an apiculus white cushion. Female inflorescence 2–3 flowered, axillary umbel; peduncle erect, 8–12 mm long, cylindrical, glabrous. Flowers urceolate, 5.6–6.2 × 3–4 mm, yellowish-green, persistent, pedicellate; pedicel up to 5 mm long, sparsely tomentose; bracteole 0.6–0.8 × 0.4–0.6 mm, ovate, brown, sparsely tomentose outside, early caducous; perianth fleshy, lobes 3, equal, acute, re-curved outward, scabrid outside; stigma short, bilobed; ovary ovate, 1.5–3 mm, glabrous. Fruits dehiscent, usually in pairs, rarely solitary, 6–8 × 4.5–6 cm, ovoid, pale yellow turning orange–yellow on maturity, apex mucronate, base cordate, longitudinal suture on one side, glabrous; rind fleshy, soft, 2–2.4 cm thick, orange–yellow; seed 4–5.8 × 3–3.5 cm, oblong, black, arillate; aril yellow, lacerated.

Phenology:—Flowering was observed in October and fruiting in April.

Distribution, habitat and biotic associations:— Myristica trobogarii was found in evergreen forest regions in two different locations of Agasthyamala Biosphere Reserve, (1) Sankily forest area having 14 mature trees (8 females and 6 males); (2) Bonacaud forest area having 8 mature trees (6 females and 2 males). It shares the habitat with other evergreen taxa such as Cinnamomum malabathrum ( Lamarck 1785: 445) Presl (1825: 46) , Knema attenuata (Wallich ex Hooker & Thomson 1855: 157) Warburg (1896: 590) , Myristica malabarica, Vateria indica Linnaeus (1753: 515), Thottea barberi ( Gamble 1924: 386) Ding Hou (1981: 315) etc.

Etymology:—The specific epithet ‘ trobogarii ’ represents Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), Pacha-Palode, Thiruvananthapuram. The name is in honour of this prestigious Institute in southern India which is at its 40 th year, where a wide range of tropical plant species, particularly from the Western Ghats are being conserved and characterized.

Paratype:— Kerala: Thiruvananthapuram district, Agasthyamala Biosphere Reserve, Bonacaud, 08°40’43.7”N,

77°09’32.3”E, 465 m a.s.l., 25 April 2019, Govind 93699 (TBGT).

Figures

FIGURE 1. A–E Myristica beddomei; F–J Myristica trobogarii; K–O Myristica malabarica; A, F & K Fruits; C, H & M Male flowers; B, G & L Androecium exposed; D, I & N Dehisced fruit with aril and seed exposed; E, J & O Rind C.S. microscopic view. Photos by Govind M. G.

FIGURE 3. A–F Myristica trobogarii Govind & M. Dan, sp. nov.; A. Leafy twig with fruits; B. Male flower; C. Female flower; D. Bracteole: adaxial & abaxial view; E. Male flower, androecium exposed; F. Female flower L. S.; G–H Myristica malabarica; G. Male flower, androecium exposed; H. Female flower L.S. Drawn from Govind 81763 by Govind M.G.